Profile & Shrink the iOS Framework
Measure size and runtime cost on device.
Profile & Shrink the iOS Framework is a free Kotlin Multiplatform Academy lesson on CoddyKit — lesson 2 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Kotlin Multiplatform Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Why Framework Size Matters
Your Kotlin code ships to iOS as a binary framework. A bloated one slows app launch and eats download size, so trimming it pays off.
Measure the Baseline First
You cannot shrink what you have not measured. Check the built .framework file size so every later change has a number to compare against.
du -h shared.framework/sharedRelease, Not Debug
Always profile the release framework. Debug builds skip optimization and carry extra symbols, giving you misleading, much larger sizes.
./gradlew linkReleaseFrameworkIosArm64Strip Debug Symbols
Symbol tables help debugging but bloat the binary. Stripping them for production shrinks the framework with no effect on behavior.
Watch Your Dependencies
Every library you pull into commonMain rides along to iOS. Each dependency adds bytes, so drop ones you do not truly need.
Dead Code Elimination
The Kotlin/Native compiler prunes unreachable code. Keeping your public API small helps it strip more of what iOS never calls.
Smaller Public Surface
Mark internal helpers as internal, not public. Exported declarations cannot be removed, so a tight surface means a leaner binary.
internal fun helper() = compute()Profile Launch Cost
Size is one thing, speed another. Use Xcode Instruments to see how long loading and initializing the framework actually takes.
Avoid Heavy Top-Level Init
Code that runs at framework load adds launch lag. Keep initialization lazy so work happens only when the feature is first used.
Bitcode Is Gone
Apple dropped bitcode, so you no longer carry it. Make sure old build settings are not still bloating your framework for nothing.
Track Size Over Time
Sizes creep up quietly. Record the framework size in CI so a sudden jump flags the commit that added the weight.
Quick Check
Recall which build configuration gives a trustworthy size reading.
Recap
You measured the release framework, stripped symbols, trimmed dependencies and the public API, profiled launch in Instruments, and tracked size in CI. 📉
Frequently asked questions
Is the “Profile & Shrink the iOS Framework” lesson free?
Yes — the full text of “Profile & Shrink the iOS Framework” is free to read here on the web, and the Kotlin Multiplatform Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Kotlin Multiplatform Academy course, upgrade to CoddyKit PRO.
What will I learn in “Profile & Shrink the iOS Framework”?
Measure size and runtime cost on device. You practise Kotlin Multiplatform Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Kotlin Multiplatform Academy?
No prior experience is required. Kotlin Multiplatform Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 2 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “Profile & Shrink the iOS Framework” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Kotlin Multiplatform Academy lesson?
Yes. Every Kotlin Multiplatform Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- Speed Up Gradle & iOS Builds
- Profile & Shrink the iOS Framework
- CI Pipelines for Android & iOS
- Crash Reporting & Store Release